Today, a rare consensus has emerged in favor of reforming our federal drug sentencing laws. This presents a historic opportunity to improve the fairness of our criminal justice system. But unless we act quickly, we risk letting the moment pass.

The Justice Department has sought to be an early innovator on this front. A year and a half ago, I launched the Smart on Crime initiative — a comprehensive effort to reorient the federal government’s approach to criminal justice. The approach focused on reducing the use of draconian mandatory minimum sentences for low-level drug offenses and deepening our investments in rehabilitation and reentry programs that can reduce the likelihood of recidivism.

Preliminary results from this effort are extremely encouraging. In the last year, federal prosecutors have gone from seeking a mandatory minimum penalty in two out of every three drug-trafficking cases to doing so in one out of two. This represents the lowest rate on record, according to the U.S. Sentencing Commission. Last year also witnessed the first overall reduction in the federal prison population in 32 years. Most impressive of all, we achieved this drop in incarceration at the same time we cut the crime rate, marking the first simultaneous reduction in both crime and incarceration rates in more than four decades.

But while it is indisputable that we are moving in the right direction, there is a limit to what the Justice Department can accomplish on its own. Moving forward, we need to build upon, and make permanent, these gains through action in Congress.

There is a clear will to act. In a time of seemingly intractable partisanship in Washington, criminal justice reform is an issue that is transcending party lines. Just over a week ago, conservative stakeholders such as Koch Industries and Americans for Tax Reform joined with progressive voices such as the Center for American Progress to form a new coalition dedicated to this cause. On Tuesday, President Obama convened a bipartisan collection of lawmakers — including Sens. Mike Lee (R-Utah), Dick Durbin (D-Ill.), Rand Paul (R-Ky.) and Cory Booker (D-N.J.) and Reps. Jason Chaffetz (R-Utah) and Bobby Scott (D-Va.) — to discuss possible congressional action. And just two days ago, Supreme Court Justices Antonin Scalia, Anthony Kennedy and Clarence Thomas joined a dissent by Justice Elena Kagan lamenting a federal criminal statute “with too-high maximum penalties.”

These unlikely alliances on what was recently one of the country’s most divisive political issues highlight the opportunity to act, and act now. As we seek to channel this bipartisan resolve, a few specific items of unfinished business should command our immediate attention.

First, although Obama signed the Fair Sentencing Act to eliminate a discriminatory 100-to-1 sentencing disparity between crack and powder cocaine, thousands of individuals who committed crimes before 2010 are still serving sentences based on the old ratio. This is unfair. Congress should pass legislation to apply that statute retroactively so that no one is sitting in prison serving a sentence that Congress, the president and the attorney general have all declared unjust.

Second, while the Justice Department has declined to seek harsh mandatory minimum sentences in cases where they are not warranted, we need to codify this approach. Congress should pass one of the multiple bipartisan bills aimed at restricting and refining those crimes to which mandatory minimums apply.

Third, in individual states, legislatures should eliminate statutes that prevent an estimated 5.8 million U.S. citizens from exercising their right to vote because of felony convictions. These unfair restrictions only serve to impede the work of transitioning formerly incarcerated people back into society.

Finally, we should seek to expand the use of federal drug courts throughout the country for low-level drug offenses. These programs provide proven alternatives to incarceration for men and women who are willing to do the hard work of recovery, and it is my hope that, in the next five years, there will be an operational drug court in every federal district — with individual states following suit.

While I will depart the Obama administration in the coming weeks — and my own formal career in law enforcement will soon draw to a close — I intend to continue this work, to promote this mission and to advance this cause. And I hope that, in the days ahead, leaders in Congress and around the country will come together to help build the fairer, more efficient and more effective criminal justice system that all Americans deserve.